1. Technical Field
The present invention relates to a sheet manufacturing apparatus.
2. Related Art
In the related art, as a sheet manufacturing apparatus, a so-called wet type sheet manufacturing apparatus is employed in which a raw material containing fibers is fed into water, is disaggregated mainly by a mechanical action, and is repulped. Such a wet type sheet manufacturing apparatus is large in size since the apparatus requires a large amount of water. Furthermore, it takes time and effort for maintenance of water treatment facilities, and energy for a drying process is increased.
Therefore, for size reduction and energy saving, a dry type sheet manufacturing apparatus in which as little water as possible is used has been proposed. For example, a technique, in which pieces of paper are defibrated into fibers by a dry type defibration machine, deinking of fibers is performed in a cyclone, the deinked fibers pass through a screen having small holes of a forming drum surface, are sucked by a suction device, are deposited on a mesh belt, and then paper is formed, is disclosed in JP-A-2012-144819.
However, in the sheet manufacturing apparatus described above, if fibers are supplied to a forming drum unit by airflow, the amount of fibers deposited on the mesh belt becomes uneven and a grammage of a sheet to be manufactured may become uneven by the airflow being disturbed. Furthermore, the inside of a housing unit accommodating the drum unit has a negative pressure and an intake air amount from a portion between the mesh belt and the housing unit may be increased due to suction of the suction device (suction unit). Thus, the amount of fibers deposited on the mesh belt becomes uneven and the grammage of the sheet to be manufactured may become uneven.